135 research outputs found
Soil erosion by landing rockets Final report
Cratering effect of descending rocket exhaust expected from soft earth landin
Recommended from our members
Decision management for the Hanford Environmental Dose Reconstruction Project
The Hanford Environmental Dose Reconstruction (HEDR) Project is in the process of developing estimates for the radiation doses that individuals and population groups may have received as a result of past activities at the Hanford Reservation in Eastern Washington. A formal decision-aiding methodology has been developed to assist the HEDR Project in making significant and defensible decisions regarding how this study will be conducted. These decisions relate primarily to policy (e.g., the appropriate level of public participation in the study) and specific technical aspects (e.g., the appropriate domain and depth of the study), and may have significant consequences with respect to technical results, costs, and public acceptability
Exploring the Foundation of Genomics: A Northern Blot Reference set for the Comparative Analysis of Transcript Profiling Technologies
In this paper we aim to create a reference data collection of Northern blot results
and demonstrate how such a collection can enable a quantitative comparison of
modern expression profiling techniques, a central component of functional genomics
studies. Historically, Northern blots were the de facto standard for determining RNA
transcript levels. However, driven by the demand for analysis of large sets of genes in
parallel, high-throughput methods, such as microarrays, dominate modern profiling
efforts. To facilitate assessment of these methods, in comparison to Northern blots,
we created a database of published Northern results obtained with a standardized
commercial multiple tissue blot (dbMTN). In order to demonstrate the utility of the
dbMTN collection for technology comparison, we also generated expression profiles
for genes across a set of human tissues, using multiple profiling techniques. No method
produced profiles that were strongly correlated with the Northern blot data. The
highest correlations to the Northern blot data were determined with microarrays
for the subset of genes observed to be specifically expressed in a single tissue in
the Northern analyses. The database and expression profiling data are available
via the project website (http://www.cisreg.ca). We believe that emphasis on multitechnique
validation of expression profiles is justified, as the correlation results
between platforms are not encouraging on the whole. Supplementary material for this
article can be found at: http://www.interscience.wiley.com/jpages/1531-6912/suppma
Genetic Heterogeneity in a Cyclical Forest Pest, the Southern Pine Beetle, Dendroctonus frontalis, is Differentiated Into East and West Groups in the Southeastern United States
The southern pine beetle, Dendroctonus frontalis Zimmerman (Coleoptera: Curculionidae) is an economically important pest species throughout the southeastern United States, Arizona, Mexico, and Central America. Previous research identified population structure among widely distant locations, yet failed to detect population structure among national forests in the state of Mississippi. This study uses microsatellite variation throughout the southeastern United States to compare the southern pine beetle's pattern of population structure to phylogeographic patterns in the region, and to provide information about dispersal. Bayesian clustering identified east and west genetic groups spanning multiple states. The east group had lower heterozygosity, possibly indicating greater habitat fragmentation or a more recent colonization. Significant genetic differentiation (θST = 0.01, p < 0.0001) followed an isolation-by-distance pattern (r = 0.39, p < 0.001) among samples, and a hierarchical AMOVA indicated slightly more differentiation occurred between multi-state groups. The observed population structure matches a previously identified phylogeographic pattern, division of groups along the Appalachian Mountain/Apalachicola River axis. Our results indicate that the species likely occurs as a large, stable metapopulation with considerable gene flow among subpopulations. Also, the relatively low magnitude of genetic differentiation among samples suggests that southern pine beetles may respond similarly to management across their range
- …